diff --git a/src/java/davmail/caldav/CaldavConnection.java b/src/java/davmail/caldav/CaldavConnection.java
index bfe9a11d..95e9d691 100644
--- a/src/java/davmail/caldav/CaldavConnection.java
+++ b/src/java/davmail/caldav/CaldavConnection.java
@@ -227,6 +227,8 @@ public class CaldavConnection extends AbstractConnection {
             }
         } else if ("PROPFIND".equals(command) && "users".equals(paths[1]) && paths.length == 4 && "calendar".equals(paths[3])) {
             sendCalendar(request, depth, paths[2]);
+        } else if ("PROPPATCH".equals(command) && "users".equals(paths[1]) && paths.length == 4 && "calendar".equals(paths[3])) {
+            patchCalendar(request, depth, paths[2]);
         } else if ("REPORT".equals(command) && "users".equals(paths[1]) && paths.length == 4 && "calendar".equals(paths[3])
                 // only current user for now
                 && session.getEmail().equalsIgnoreCase(paths[2])) {
@@ -411,6 +413,14 @@ public class CaldavConnection extends AbstractConnection {
         sendHttpResponse(HttpStatus.SC_MULTI_STATUS, null, response, true);
     }
 
+    public void patchCalendar(CaldavRequest request, int depth, String principal) throws IOException {
+        CaldavResponse response = new CaldavResponse();
+        response.startMultistatus();
+        // just ignore calendar folder proppatch (color not supported in Exchange)
+        response.endMultistatus();
+        sendHttpResponse(HttpStatus.SC_MULTI_STATUS, null, response, true);
+    }
+
     protected String getEventFileNameFromPath(String path) {
         int index = path.lastIndexOf('/');
         if (index < 0) {